Multi-station condition-responsive alarm system



H. N. ROSS Jan. l0, 1956 MULTI-STATION CONDITION- RESPONSIVE ALARMSYSTEM 2 Sheets-Sheet 1 Filed March 5, 1954 H. N. ROSS 4 Jan. 10, 1956MULTI-STATION CONDITION-RESPONSIVE ALARM SYSTEM Filed March 5, 1954 2Sheets-Sheet 2 INVENTOR. HUGH N. Ross BY rroRA/EY n Nu WM. e@

UnitedStates Patent O MULTI-STATION CONDITION-RESPONSIVE ALARM SYSTEMHugh N. Ross, Montgomery County,

American Instrument Company, Inc., Md.

Md., assignor to Silver Spring,

This invention relates to electrical alarm systems, and moreparticularly to a relay system for operating both a common alarm deviceand individual alarm devices at respective stations from signal contactsin a multi-station, printing-type recorder.

A main object of the invention is to provide a novel and improvedelectrical alarm system which involves simple components, which isreliable in operation, and which provides continuous supervision of aplurality of stations which may be at different locations and whereinthe alarm condition for selected groups of stations may be differentfrom the alarm condition for other groups of stations.

A further object of the invention is to provide an improved electricalalarm system which includes both visual and audible alarm devices, saidsystem requiring only an intermittently closing alarm contact, andrequiring only an intermittently closing contact to return the system tonormal automatically.

A still further object of the invention is to provide an improvedmultiple-station alarm system which operates a common audible alarmdevice but wherein each station has a separate visual alarm device, thesystem being so arranged that any station can be in either an alarmcondition or a normal condition without interacting with the otherstations, the system being provided with means for silencing the commonaudible alarm device without causing the extinction of the visiblesignal at a station subjected to alarm conditions, said visible signalcontinuing until a normal condition for the station has been resumed.

Further objects and advantages of the invention will become apparentfrom the following description and claims, and from the accompanyingdrawings, wherein:

Figure l is a schematic diagram. showiaj' the main elements of animproved multi-station alarm system constructed in accordance with thepresent invention.

Figure 2 is a wiring diagram of the electrical connections of theelements of one of the stations of the system diagrammaticallyillustrated in Figure l.

Referring to the drawings, the system is applied to a plurality ofstations, comprising the sations A, B, etc., which may be physicallyseparated by substantial distances, and wherein supervision of a varyingcondition, such as temperature, humidity, etc., for the respectivestations is desired.

Associated with the system is a conventional recordingcondition-responsive instrument which is successively connected to aplurality of remote sensing devices by a timing motor 96 and which isprovided with an indicating element 11, such as an indicating pointer.Mechanically linked in any suitable manner to the indicating element 11is a rectilinearly movable cam bar 12 formed with spaced cam portions13, 14, ete., corresponding to different zones on the scale of thecondition-responsive instrument. Designated at 15, 16, etc., arerespective cam follower elements which are arranged to be individuallyengaged by dilerent cam portions 13, 14, etc.,

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as the indicating element 11 moves into the respective scale zonescorresponding to said cam portions. The respective cam follower elementsare provided with suitable guide means of a conventional natureconstraining the follower elements to paths of movement fixed inrelation to the path of movement of the cam bar 12, for example,perpendicular to said cam bar.

Mechanically linked to the respective cam follower elements 15,16, etc.,are the respective movable switch contact poles 17, 1S, etc., havinglower stationary contacts 19, 20, etc., normally engaged by the switchpoles and upper stationary contacts 21, 22, etc., engaged by the polesunder alarm conditions, namely, when the cam follower elements l5, 16,ete., engage their associated cam portions 13, 14, etc., as will be seenfrom Figure l.

The upper contacts 21, 22, etc., are connected to respective alarm lines23, 24, etc., associated with the respective condition zones, and thelower contacts 19, 20, etc.` are connected to respective normalcondition lines` 25, 26, etc., associated with the respective normalcondition values of the system.

The respective poles 17, 18, etc., are connected to respective conditionzone" conductors 27, 28, etc., as shown. Thus, each of the conductors27, 28, etc., is associated with a zone on the scale of thecondition-indicating instrument, corresponding to a respective camportion 13, 14, etc.

Designated at 29 is a zone selector device driven by timer motor 96 andsynchronized with a selector 43 for setting the system to give an alarmwhen the condition being supervised for a selected group of stations isin a zone considered abnormal for this group of stations.-

Thus, the device 29 may comprise a movable switch contact 30continuously engaging a conductive member 31 and being selectivelyengageable with a plurality of contacts 1, 2, 3, 4, 5, 6, etc., asdiagrammatically illustrated in Figure l. tacts 1, 2 and 3 are connectedto one zone conductor, such as the zone conductor 27, and others of thecontacts are connected to other zone conductors, such as to zoneconductor 28. The respective stations are connected to selected zonewires, such as to zone wires 23, 25, as by wires 32, 33. The respectivestations are connected to the zone wires associated with the respectivecondition zone conductors 27, 28, etc., corresponding to the respectivezones of the supervised condition, such as temperature, humidity, or thelike, considered to be abnormal for the respective stations. To set thesystem to provide such supervision, the movable switch contact 30is'adjusted to engage a contact l, 2, 3, etc., connected to the propercondition zone conductor. For example, in Figure 1, switch contact 30 isset to electrically connect zone conductor 27 to conductive member 31,thus setting the system to provide an alarm if the abnormal zone of thesupervised condition for any of the stations A," B, etc., connected tozone wires 23 and 25 exists, since, if said abnormal zone exists, thecam follower 15 will be engaged by cam portion 13 and cause pole 17 tobe moved into engagement with contact 21.

Conductor 31 is connected by a wire 34 to a first line wire 35.Designated at 36 is a horn having one terminal thereof connected by awire 37 to line wire 35. The other terminal of the horn is connected toa wire 38. The respective stations of the system are connected to wires35 and 38 by respective sets of wires 39 and 40. Designated at 41 is asecond line wire. The respective stations of the system are connected tosaid second line wire 41 by respective wires 42.

Line wires 35 and 41 are connected to the terminals of a suitable sourceof current.

Designated generally at 43 is a station selector, which comprises amovable contact arm 44 successively en- Certain of the contacts, forexample, congageable with respective contacts 45 which are respectivelyconnected by wires 1', 2', 3', etc., to'the respective stations A, B,etc. timer motor 96 which drives the arm 44 and which also drives anotched cam 46. The periphery of said cam is engaged by the dependingpawl element 47 of a pivoted switch arm 48, which is thus intermittentlyengageable with a stationary contact 49 responsive to the rotation ofcam 46. The timing motor 96 moves arm 44 successively to diierentcontacting positions engaging the successive contacts 45, correspondingto the different stations A, "B, etc. The arm 44 remains in contact witheach element 45 for a given period and then is moved into contact withthe next element 45. The periods of contact are synchronized with theprinting periods of the recorder. The switch pole 48 engages contact 49for a short time near the end of the contact period of arm 44 with anelement 45, and printing occurs near the end of said contact period,shortly after pole 48 engages contact 49. Pole 48 is disengaged fromcontact 49 before the end of the printing period and while arm 44 stillengages the contact element 45.

Thus contacts 48, 49 close for a short period immediately before the endof the cycle, namely, before arm 44 is moved into its next contactingposition with an element 45.

Arm 48 is connected by a wire 50 to arm 44. Contact 49 is connected toline wire 41. The respective stations are connected to a wire 52 byrespective wires 53. Wire 52 is connected to line wire 41 through anormally closed push button switch 51.

Referring to Figure 2, a schematic wiring diagram of station A isdisclosed, the other stations of the system being identical' to stationA. As shown, the station comprises the three normally deenergized relays54, 55 and 56. Relay 54 has the respective poles 57, 58, 59 and 60. Pole57 is engageable with a stationary contact 61, pole 58 is engageablewith a stationary contact 62, and pole 59 is engageable with astationary contact 63, when the relay 54 is energized. Normally, pole 58engages a stationary contact 64 and pole 60 engages a stationary contact65. Pole 58 is of the make-beforebreak type, namely, pole 58 engagescontact 62 before disengaging contact 64, and vice versa.

Relay 55 has the respective poles 66, 67, 68 and 69. Pole 66 isengageable with a stationary contact 70, pole 67 is engageable with astationary contact 71, pole 68 is engageable with a stationary contact72, and pole 69 is engageable with a stationary contact 73, when therelay 55 is energized. Normally, pole 67 engages a stationary contact 74and pole 68 engages a stationary contact 75. Poles 67 and 68 are of themake-before-break type.

Relay 56 has the respective poles 76 and 77, which normally engagerespective stationary contacts 78 and 79.

Connected in parallel with relay 54 are the signal lamps 80 and 81.

The lower terminal of relay 54, as viewed in Figure 2, is normallyconnected to wire 1 by a wire 82, pole 58, contact 64, and a Wire 83.The upper terminal of said relay is connected by a wire 84 to pole 76.Contact 78 of said pole is connected by a wire 85 to pole 59. Pole 66 ofrelay 55 is connected to wire 85 by a wire 86.

The lower terminal of relay 55 is normally connected to wire 83 by awire 87, pole 67, and contact 74. The upper terminal of relay 55 isnormally connected to wire 23 by a Wire 88, pole 77, contact 79, a Wire89, pole 68, contact 75, a wire 90, contact 65, pole 60, and wire 32.

The lower terminal of relay 56 is connected to wire 83. The upperterminal of said relay is connected by a wire 92 to contact 61 of relay54. Pole 57 of relay 54 is connected to wire 25 by the Wire 33.

Contact 62 of relay 54 is connected by the wire 42 to line wire 4l. Pole69 of relay 55 is connected to wire 42 by a wire 93. Contact 63 of relay54 is connected by a wire 39 to the other line wire 35.

The device 43 includes a Contact 70 of relay 55 is connected to wire 39by a wire 94. Contact 72 of said relay is connected to wire 94 by awireV 95. Contact 71 of said relay is connected to wire 52 by the wire53. Contact 73 of said relay is connected to wire 38 by the wire'40. Forpurposes of describing the operation of the system, 1t will be assumedthat zone selector switch arm 30 engages contact 1, as shown in Figures1 and 2, and that switch pole 17 engages alarm contact 21, as a resultof the existence of an alarm condition for station A. The timer 96causes pole 44 to engage the contact 45 connected to wire 1 for a deniteinterval of time. During said interval, the oscillating switch pole 48engages contact 49. This energizes relay 55 through a circuit comprisingline wire 41, contact 49, pole 48, wire 50, pole 44, contact 45, wirel'fwire 83, contact 74, pole 67, wire 87, relay 55, wire 88, pole 77,contact 79, wire 89, pole 68, contact 75, wire 90, contact 65, pole 60,wire 32, wire 23, pole 17, contact 1, switch arm 30, contact 31, wire34, and line wire 35.

Before poles 67 and 68 disengage from contacts 74 and 75, said polesengage contacts 71 and 72. This establishes a holding circuit for relay55 comprising line wire 41, push button switch 51, wire 52, wire 53,contact 71, pole 67, wire 87, relay 55, wire 88, pole 77, wire 89, pole68, contact 72, wires 95, 94, wire 39 and line wire 35.

The energization of relay 55 causes pole 69 to engage contact 73 andenergize horn 36 through a circuit comprising line wire 41, wire 42,wire 93, pole 69, contact 73, wire 40, horn 36, and line wire 35.

The energization of relay 55 also causes pole 66 to engage contact 70,whereby relay 54 is energized through a circuit `comprising line wire41, contact 49, pole 48, wire 50, pole 44, contact 45, wire 1', wire 83,contact 64, pole 58, wire 82, relay 54, wire 84, pole 76, contact 78,wire 85, wire 86, pole 66, contact 70, wire 94, wire 39, and line wire35.

The signal lamps and 81, connected in parallel with relay 54, are alsothus energized.

Before pole 58 disengages from contact 64, it engages contact 62 andestablishes a holding circuit for relay 54, comprising line wire 41,wire 42, contact 62, pole 58, wire 82, relay 54, wire 84, pole 76,contact 78, wire 85, pole 59, contact 63, wire 39, and line wire 35.

Thus, the horn 36 will give an audible signal of the alarm condition,and the signal lamps 80 and 81 at the station concerned, for example,station A, will give a visual signal of said alarm condition.

The horn 36 can be silenced by deenergizing relay 55, to cause pole 69to disengage from contact 73. This is done by opening the push buttonswitch 51, whereby the holding circuit for relay 55 is broken. Sincepole 58 is now disengaged from contact 64, relay 55 will remaindeenergized. The visual signals provided by lamps 80 and 81 willcontinue to be given as long as the alarm condition continues.

When the condition again becomes normal, pole 17 dis engages fromcontact 21 and engages contact 19. This energizes relay 56 when wire 1is again connected to line wire 41, through a circuit comprising linewire 41, Contact 49, pole 48, wire 50, pole 44, contact 4S, wire 1',wire 83, relay 56, wire 92, contact 61, pole 57, wire 33, wire 25, pole17, contact 1, pole 30, contact 31, wire 34, and line wire 35.

The energization of relay 56 breaks the holding circuits for relays 54and 55 respectively at the contacts 76, 78 and 77, 79 of relay 5,6. Atthe same time, the energizing circuit for relay 56 is broken at contacts57, 61 of relay 54, causing relay 56 to become deenergized, restoringthe system to its original state.

It will be thus apparent that if normal condition occurs before the horn36 has been silenced manually, both the horn and the signal lamps 80, 81will become deenergized.

The sequence of events above described is for one of s the stations ofthe system. All of the stations operate the common horn 36, but eachstation has its separate signal lamps. Any of the stations can be in anyof the phases of its cycle of operations without interacting with ytheother stations.

While a specific embodiment of an improved multi-station,condition-responsive alarm system has been disclosed in the foregoingdescription, it will be understood that various modifications within thespirit of the invention may occur to those skilled in the art. Thereforeit is intended that no limitations be placed on the invention Y exceptas defined by the scope of the appended claims.

What is claimed is:

l. In combination, a condition-responsive device having an alarmposition and a normal position, a common audible alarm device, aplurality of stations, a respective visual alarm device connected toeach station, first relay means at each station, means for energizingsaid common audible alarm device and the visual alarm device of astation when said first relay means thereof becomes energized, meansenergizing said first relay means when said condition-responsive deviceassumes said alarm position, second relay means at each station, meansenergizing said second relay means when the condition-responsive devicemoves from alarm to normal position, means deenergizing said first relaymeans in response to the energization of said second relay means, andmeans deenergizing said second relay means responsive to thedeenergization of said first relay means.

2. In combination, a condition-responsive device having an alarmposition and a normal position, a common .audible alarm device, aplurality of stations, a respective visual alarm device connected toeach station, first normally deenergized relay means at each station,means for energizing said common audible alarm device and the visualalarm device of a station when said first relay means thereof becomesenergized, means energizing said first relay means when saidcondition-responsive device assumes said alarm position, second normallydeenergized relay means at each station, means energizing said secondrelay means when the condition-responsive device moves from alarm tonormal position, means deenergizing said first relay means in responseto the energization of said second relay means, and means deenergizingsaid second relay means responsive to the deenergization of said firstrelay means.

3. In combination, a condition-responsive device having an alarmposition and a normal position, a common audible alarm device, aplurality of stations, a respective visual alarm device connected toeach station, first relay means at each station, means for energizingsaid common audible alarm device and the visual alarm device of astation when said first relay means thereof becomes energized, means forindependently deenergizing said common audible alarm device, meansenergizing said first relay means when said condition-responsive deviceassumes said alarm position, second relay means at each station, meansenergizing said second relay means when the condition-responsive devicemoves from alarm to normal position, means deenergizing said first relaymeans in response to the energization of said second relay means, andmeans deenergizing said second relay means responsive to thedeenergization of said first relay means.

4. In combination, a condition-responsive device having an alarmposition and a Vnormal position, a common audible alarm device, aplurality of stations, a respective visual alarm device connected toeach station, first relay means at each station, a source of current,means intermittently connecting the respective stations at differenttimes to said source of current, means for energizing said commonaudible alarm device and the visual alarm device of a station from saidsource when said first relay means i thereof becomes energized, meansenergimng said first relay means from said source when saidcondition-responsivedevice assumes said alarm position, second relaymeans from said source when the condition-responsive device moves fromalarm to normal positron, means deenergizing said tirst relay means inkresponse to the energization of said second relay means, and meansdeenergizing said second relay means responsive to the deenergization ofsaid first relay means.

5. In combination, a condition-responsive device having an alarmposition and a normal position, a common audible alarm device, aplurality of stations, a respective visual alarm device connected toeach station, first normally deenergized relay means at each station, asource of current, means intermittently connecting the respectivestations at different times to said source of current, means forenergizing said common audible alarm device and the visual alarm deviceof. a station from said source when said first relay m'eans thereofbecomes energized, means for independently deenergizing said commonaudible alarm device, means energizing said first relay means from saidsource when said condition-responsive device assumes said alarmposition, second normally deenergized relay means at each station, meansenergizing said second relay means from said source when thecondition-responsive device moves from alarm to normal position, meansdeenergizing said first relay means in response to the energization ofsaid second relay means, and means deenergizing said second relay meansresponsive to the deenergization of said first relay means.

6. In combination, a condition-responsive device having an alarmposition and a normal position, a common first alarm device, a pluralityof stations, a respective additional alarm device connected to eachstation, first relay means at each station, means for energizing saidfirst alarm device and the additional alarm device of a station whensaid first relay means thereof becomes energized, means energizing saidfirst relay means when said condition-responsive device assumes saidalarm position, second relay means at each station, means energizingsaid second relay means when the condition-responsive device moves fromalarm to normal position, means deenergizing said first relay means inresponse to the energization of said second relay means, and meansdeenergizing said second relay means responsive to the deenergization ofsaid first relay means.

7. In combination, a condition-responsive device having an alarmposition and a normal position, a common first alarm device, a pluralityof stations, a respective additional alarm device connected to eachstation, first relay means at each station, a source of current, meansintermittently connecting the respective stations .at different times tosaid source of current, means for energizing said first alarm device andtheA additional alarm device of a station from said source when saidfirst relay means thereof becomes energized, means energizing saidrstrelay means from said source when said condition-responsive deviceassumes said alarm position, second relay means at each station, meansenergizing said second relay means from said source when thecondition-responsive device moves from alarm to normal position, meansdeenergizing said first relay means in response to the energization ofsaid second relay means, and means deenergizing said second relay meansresponsive to the deenergization of said first relay means.

8. In combination, a condition-responsive device having an alarmposition and a normal position, a first alarm device, a plurality ofstations, a respective additional alarm device connected to eachstation, first relay means at each station, means intermittentlyconnecting the respective stations at different times to saidcondition-responsive device, means for energizing said first alarmdevice and the additional alarm device of a station when said firstrelay means thereof becomes energized, means energizing said first relaymeans when said condition-responsive device assumes said alarm position,second relay means at each station, means energizing said second relaymeans when the condition-responsive device moves from alarm to normalposition, means deenergzing said rst relay means in response to theenergization of said second relay means, and means deenergzing saidsecond relay means respon sive to the deenergization of said rst relaymeans.

Rehn-cu Cited in the tile of this patent UNITED STATES PATENTS BrownJan. 23, 1923 Field July 2, 1929 Proctor Jan. 3, 1950 Odell et al. Dec.l1, 1951

